Mower cutting device

ABSTRACT

THE PRESENT INVENTION RELATES TO A CUTTING DEVICE FOR USE WITH ROTARY POWER MOWERS. MORE PARTICULARLY THE CUTTING DEVICE FOR SUCH USE IS COMPRISED OF A CUTTING PLATE HAVING THE COMBINATION OF A STRAIGHT CUTTING EDGE AND A SERIES OF SAW-TEETH ALONG ITS OUTER END ARRANGED IN A PARTICULARLY ADVANTAGEOUS CONFIGURATION. THIS PARTICULAR COMBINATION OF A LEADING KNIFE-LIKE CUTTING EDGE COMBINED WITH THE PARTICULAR SAWTOOTH CONFIGURATION PROVIDES A CUTTING MEANS WHICH WILL NOT BECOME BOUND UP WITH THE CUTTINGS AND ALSO AVOIDS WEDGING AND BINDING EXPERIENCED WITH STRAIGHT KNIFE-LIKE CUTTING EDGES.

y 9. 1973 E. v. STAIR MOWER CUTTING DEVICE 2 Sheets-Shaet 1 OriginalFiled Aug. 27, 1965 FIG.|

FIG. 6

May 1973 v, 5TA|R Re. 27,647

MOWER CUTTING DEVICE Original Filed Aug. 27. 1965 2 Sheets-Shut 2 UnitedStates Patent 27,647 MOWER CUTTING DEVICE Eugene V. Stair, Box 238, Rte.1, Caddo, Okla. 74720 Original No. 3,482,380, dated Dec. 9, 1969, Ser.No.

483,203, Aug. 27, 1965. Application for reissue Nov.

23, 1970, Ser. No. 92,333

Int. Cl. A0111 55/18 U.S. Cl. 56295 8 Claims Matter enclosed in heavybrackets [II appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE The present invention relates to a cuttingdevice for use with rotary power mowers. More particularly the cuttingdevice for such use is comprised of a cutting plate having thecombination of a straight cutting edge and a series of saw-teeth alongits outer end arranged in a particularly advantageous configuration.This particular combination of a leading knife-like cutting edgecombined with the particular sawtooth configuration provides a cuttingmeans which will not become bound up with the cuttings and also avoidswedging and binding experienced with straight knife-like cutting edges.

This invention relates to cutting devices and in particular a cuttingdevice to be used with a rotary type mower.

While the present invention is not necessarily confined to such a use,it is particularly adapted to rotary type mowers customarily utilized incleaning up land infested with heavy growths of weeds, briars, bushes,or small trees such as cutover timber land, ranch land, and highwayright-of-ways.

One of the main difliculties experienced with the use of present rotarymowers for these purposes is the presence of tree stumps and small treeswhich these rotary mowers are not able to cut.

Cutting devices presently in use with rotary power mowers for the mostpart have straight cutting edges. These cutting devices will onlyoperate properly and without damage to the mower when the growth islight and free of stumps because thick cuttings tend to clog and bindabout the straight cutting edges.

For the most part, the only remedy introduced for this problem which hashad any semblance of success has been to increase the horsepower drivingthe blades. As is evident, such a remedy is not only costly, but issomewhat ineffective.

While toothed configurations have been provided along the leading edgesof rotary mower blades in an attempt to improve their cuttingcharacteristics, such blades have not proven effective for cutting brushwhich is heavy and contains small trees and tree stumps. The toothedconfigurations previously provided along the leading edges of rotarymower blades have been of a rough edge or step cut knife variety,incapable of freeing the cuttings and therefore afflicted with the samewedging and binding experienced with straight knife-like cutting edges.

I have discovered that the clogging, binding and stalling experiencedwhen cutting heavy growths with a rotary mower, can be overcome byproviding a cutting device which in addition to a straight knife-likeleading edge also possesses a cutting edge at its outer periphery havinga special saw tooth configuration which will not become bound up withcuttings.

With the rotation of my new and improved cutting de vice, the saw toothedge is drawn through the heavy growth of stalks, small trees, stumpsand other vegetation while the straight knife-like leading edge of thecutting ice device severs the lighter growths of vegetation. Thus mymower is designed to travel slower through heavy growths of vegetationso that the saw toothed edges do all the cutting than through lightvegetation wherein the severing of the vegetation is accomplished by thefull length of the straight knife-like leading edge of the cuttingdevice.

Accordingly, it is an object of the present invention to provide animproved cutting device for a rotary type mower which can be used incutting heavy growths of bush and tree stumps.

Another object of the present invention is to provide a cutting devicepossessing a knife-like blade at its leading edge and a series ofcutting saw teeth set in a definite configuration positioned at itsouter extremity.

Another object of the present invention is to provide a cutting devicefor cutting brush and tree stumps which can be readily attached toconventional rotary mowers and land clearing machines.

Another object of the present invention is to provide a cutting devicefor brush and tree stumps which will foster the development of newtimber clearing machines powered by farm and ranch type tractors in themedium horsepower range.

Still another object of the present invention is to provide a cuttingdevice for cutting heavy growth and tree stumps which does not have toexpend more than minimal horsepower.

Other details, objects and advantages of the present invention willbecome apparent from the following description of the present embodimentthereof, taken in conjunction with the drawings which accompany and formpart of the specification.

In the drawings:

FIG. 1 is a partly broken away side elevation of a rotary mowerembodying the invention.

FIG. 2 is an enlarged elevation view of the cutter illustrated in FIG.1.

FIG. 3 is an enlarged top view of one of the cutting devices.

FIG. 4 is an enlarged front view of the cutting device shown in FIGS.1-3.

FIG. 5 is a bottom view of the cutting device as embodied in a rotarymower of the disc variety.

FIG. 6 is a sectional view of the cutting plate of the present inventionattached in a disc type rotary mower.

Referring more particularly to the figures of the drawing there is shownin FIGURE 1 a rotary mower 10 comprised of a frame member 12 whichsupports a gear box 14 driven by a drive shaft 16 and universal joint18. The frame 12 carries a top cover 20 to which is attached a dependingcutter housing 22. The machine rides on a pair of wheels 24 attached tothe sides of the housing.

The blade holder of the invention consists of one or more bars 26. Meansare provided for attaching said one or more bars 26 substantially attheir midpoint to shaft 28 which extends through the top cover 20 to thegear box 14. To determine the position of the bar on shaft 28, and hencethe elevation from the ground, one or more washers 30 may also heslipped on the shaft. The assembly is then held removably in place bymeans of lock washer 30 and nut 31.

The ends of each of the bars 26 as shown in FIGURE 2 are provided withan aperture 32 for receiving a bolt 38 for attaching the cutting plates34 thereto.

Each of the cutting plates 34 as illustrated in FIG. 4 comprise anelongated body of steel or the like with an aperture positioned at 40for the attachment of the cutting plate to the end of one of the bars.

To determine the position of the cutting plate with regard to the bars,and hence to its relation from the ground, one or more washers 36 aswell as an adapter spacer 37 may be placed on the bolt 38 between thecutting plate 34 and bar 26. On the trailing edge of the adapter spacertwo flanges or guards 44 are provided, one of which extends upwardl andother downwardly to insure forward rigidity of the cutting plate 34 inrelation to the bar 26. It is noted that if preferred, the adapterspacer may be eliminated by providing each of the cutting plates with anupwardly extending flange.

A portion of the leading edge 46 of each of said cutting platespossesses a knife-like straight edge 47, while one end of said cuttingplate 34 is formed with a plurality of alternately, aligned spacedcutting saw teeth 50, the leading edges of which are sharpened. Thesealternately aligned spaced cutting saw teeth 50 form a first 52, and asecond 54, series of aligned teeth with an acute angle formedtherebetween. These cutting saw teeth have the ability to cut vegetablematter which would be impossible to cut with a straight cutting edge orrough toothed edge knives of the prior art.

The plates 34 bearing the cutting teeth are formed with the saw teethclosest to the trailing edge 60 of the plates extending a greaterdistance outwardly from the shaft than the saw teeth closest to theplates leading edge. This configuration enables the saw teeth to advanceinto the vegetation at a progressive rate and is a further aid in theprevention of binding common in rotary mowers of the prior art.

It is to be pointed out that with the present invention any number ofcutting plates may be provided mounted on bars, mounted at right anglesto each other, or they may be mounted on an equivalent constructionwherein the bars are formed integrally from a single piece, such as adisc shown in FIG. 5.

A rotary mower equipped with my improved cutting device can also be usedto cut down large trees which a tractor or a mower cannot push down. Asillustrated in FIG. I, a section 80 of the mower housing may be maderemovable so that the saw tooth cutting edges can be placed in directcontact with the trees or stumps to be cut.

In FIG. there is shown an embodiment of the present invention as appliedto a disc-type rotary mower of the variety having a single trailingwheel. In this embodiment section 81 of the mower housing may be maderemovable and the mower backed into contact with trees or high stumps tobe cut. In order to insure forward rigidity of the cutting plate 34 inrelation to the disc 83, as shown in FIG. 6, an adapter spacer 85 isplaced between the cutting plate 34 and the disc 83, on bolt 39. Theadapter spacer 85 possesses an upwardly extending flange 87 whichengages the outer periphery of the disc 83, and a downwardly extendingflange 89 which engages the trailing edge of the cutting blade 34.

It will be apparent from the foregoing that I have disclosed an improvedcutting device for rotary mowers which will enable the rotary mower toclear heavy brush and stumps and cut down trees without the binding andclogging and the expenditure of unnecessary horsepower which exists inrotary mowers of the prior art.

It is also apparent that not only is my cutting device adaptable toconventional rotary mowers and land clearing machines but that it willundoubtedly foster the development of new timber clearing machinespowered by farm and ranch-type tractors in the medium horsepower range.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics. The present embodimentsare therefore considered in all respects illustrative and notrestrictive, the scope of the invention being indicated by the appendedclaims rather than by the foregoing, and all changes which come withinthe meaning and range of equivalency of the claims are thereforeintended to be embraced therein.

What is claimed and desired to be secured by the United States LettersPatent is:

1. A cutting device for a rotary mower having a power driven rotaryshaft, comprising blade holdin means, attaching means on said bladeholding means for attaching said blade holding means to said rotaryshaft, at least one cutting plate having a straight cutting edge formedon its leading edge and a plurality of alternately aligned spacedcutting saw-teeth on one of its longitudinal ends extending generallybetween its leading edge and trailing edge, the leading edges of saidcutting saw-teeth being sharpened, securing means for securing saidcutting plate to said blade holding means with its saw-toothed endprojecting longitudinally outward from said blade holding means, saidcutting saw-teeth being formed in a first and second aligned serieshaving an acute angle therebetween, and the cutting saw-teeth closest tosaid trailing edge of said cutting plate extending a greater distanceoutwardly from said rotary shaft than the teeth closest to the cuttingplate leading edge.

2. A cutting device as defined in claim 1, comprising means associatedwith said blade holding means and said cutting plate to maintain saidplate rigid in a forward direction relative to said blade holding means.

3. A cutting device for a rotary mower as defined in claim 2 whereinsaid associated means comprises a flange on said plate which cooperateswith said securing means in maintaining said plate rigid in a forwarddirection in relation to said blade holding means.

4. A cutting device for a rotary mower as described in claim 2 whereinsaid securing means for each of said cutting plates includes an adapterspacer having an upwardly and a downwardly extending flange associatedwith said blade holding means and said cutting plate for maintainingsaid plate rigid in relation to said blade holding means.

5. A rotary mower for cuttin heavy growths of weeds, briars, bushes,stumps and trees, comprising a housing having a substantially horizontaltop cover plate secured to the upper edge of said housing, meanssupporting said housing a predetermined distance above the ground, ashaft mounted in said top cover for rotation about an axis normal to theplane of said top cover plate, blade holding means rigidly secured tosaid shaft, a cutting plate rigidly mounted at each end of said bladeholding means, the free ends of said cutting plates being receivedwithin said housing, each of said cutting plates including a straightknife-like leading edge and a plurality of alternately aligned spacedcutting saw-teeth on its free longitudinal end extending generallybetween its leading edge and trailing edge, the leading edges of saidcutting saw-teeth being sharpened, said cutting saw-teeth being formedin a first and second aligned series having an acute angle therebetween,and the cutting saw-teeth closest to the trailing edge of the cuttingplates extending a greater distance outwardly from the rotary shaft thanthe teeth closest to the leading edge of the cutting plates.

6. A rotary mower for cutting heavy growths of weeds, briars, bushes,stumps, and small trees, as described in claim 5 wherein a portion ofsaid housing is removable so that large trees and high stumps which willnot fit under said housing can be brought into contact with the cuttingsaw teeth on the cutting plates.

7. A cutting device for a rotary mower having a power driven rotaryshaft, blade holding means attached to and extending laterally from saidshaft and having an outer edge, at least one cutting blade pivorallyconnected at one and adjacent the outer edge of said blade holdingmeans, the other end of said cutting blade having a knife-like cuttingedge formed on its leading edge and a plurality of cutting teeth on itsouter peripheral edge extending between its leading edge and trailingedge, the cutting teeth closest to said trailing edge extending agreater distance outwardly from said rotary shaft than the teeth closestto said leading edge, positioning means associated with said bladeholding means and said cutrting blade to maintain said blade in apredetermined operative radial cutting position as said shaft and bladeholding means rotate in a forward direction, and said cutting bladeapproaches the material to be cut, said positioning means permittingsubstantially unrestrained pivotal movement of said CH!- tin blade in arearward direction, if necessary, to prevent breakage thereof.

8. A cutting device as defined in claim 7, comprising a plurality ofcutting blades pivotally connected to said blade holding means, and aplurality of said positioning means each associated with a cutting bladefor positioning each of said blades independently of the other blades.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS ANTONIO F. GUIDA, Primary Examiner

